The present invention relates to a suspension and control linkage for a blade support frame of a motor grader and more specifically relates to a suspension and control linkage of the type disclosed in U.S. Pat. No. 3,739,861 granted to Johnson et al on June 19, 1973.
The suspension and control linkage disclosed in the abovementioned Johnson et al patent includes a pair of bell cranks pivotally mounted on opposite sides of the main fore-and-aft extending arched frame of the motor grader for movement about respective fore-and-aft extending axes. A crossbar extends beneath the frame and has its opposite ends respectively pivotally connected to first arms of the bell cranks. A pair of blade lift actuators are respectively pivotally connected between the blade support frame and respective second arms of the bell cranks and a side shift actuator is provided between the crossbar and the blade support frame. The crossbar is provided with a plurality of holes along its length and a normally spring engaged hydraulically releasable locking pin is mounted on the frame and operative to selectively enter one of the holes to fix the blade support frame in a desired position.
The patented linkage is not fashioned as well as it might be for increased visibility and to the end of permitting a large amount of bell crank rotation in order that the blade may be operated to positions giving the machine more versatility.